From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herve Codina Date: Tue, 6 Jul 2021 16:24:53 +0200 Subject: [Buildroot] [PATCH v2 10/18] package/pkg-generic.mk: detect files overwritten in TARGET_DIR and HOST_DIR In-Reply-To: <20210706142501.951345-1-herve.codina@bootlin.com> References: <20210706142501.951345-1-herve.codina@bootlin.com> Message-ID: <20210706142501.951345-11-herve.codina@bootlin.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net From: Thomas Petazzoni Without per-package directory support, a package can happily overwrite files installed by other packages. Indeed, because the build order between packages is always guaranteed, Buildroot will always produce the same output. However, with per-package directory support, it is absolutely critical that a given package does not overwrite files already installed by another package, due to how the final aggregation is done to create the complete target/, staging/ and host/ folders. Unfortunately, we currently don't have anything in Buildroot that detects this situation. We used to have check-uniq-files, but it was dropped in commit 2496189a4207173e4cd5bbab90256f911175ee57. This commit is a new implementation of such a detection, which is based on calculating and verifying MD5 hashes of installed files: the calculation is done at the beginning of the configure step, the verification during the newly introduced "install" step that takes place after all installation steps. Since preventing file overwrites is really only needed when per-package directory support is used, and due to this verification having some overhead, it is only enabled when BR2_PER_PACKAGE_DIRECTORIES=y. This additional verification cost is however not too bad as on average, with per-package directory support, the per-package target/ and host/ directories will contain less files than with a build that doesn't use per-package directory support. This helps a bit in mitigating the additional cost of this verification. Note that we are not handling separately HOST_DIR and STAGING_DIR, like we're doing with the pkg_size_{before,after} functions. Instead, the verification on HOST_DIR walks down into the STAGING_DIR. During per-package build, original files are modified by fixup-libtool-files and fixup-python-files calls. But since these fixups modify files using sed --in-place, these modifications are done using a temporary file and a call to rename. Rename breaks the hardlink to the original file and leave the temporary file in per-package TARGET dir. As the original file is not modified, this is no longer considered as an overwrite. This patch simply considers that what is done by fixup-libtool-files and fixup-python-files is part of the original snapshot used to detect overwrites. And so, the original snapshot is taken after fixup-libtool-files and fixup-python-files calls. Signed-off-by: Thomas Petazzoni Signed-off-by: Herve Codina --- This commit is retreived from Thomas's work. The first version was discussed https://patchwork.ozlabs.org/project/buildroot/patch/20200430095249.782597-9-thomas.petazzoni at bootlin.com/ This new version was not already submitted by Thomas or I missed it. Compared to the first version, this patch has an improved commit message and generates the md5sum snapshot using 'LC_ALL=C find $(1) -type f -print0 | xargs -0 -r md5sum > $($(PKG)_DIR)/.files$(2).md5;' instead of 'cd $(1); LC_ALL=C find . -type f -exec md5sum {} \; > $($(PKG)_DIR)/.files$(2).md5' Changes v1 to v2: - Added note about why fixup-{libtool,python}-files are not considered overwrites and so take the overwrite snapshot after fixup-{libtool,python}-files call. - Removed 'LC_ALL=C' package/pkg-generic.mk | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk index 8c19522fd8..3e1030a495 100644 --- a/package/pkg-generic.mk +++ b/package/pkg-generic.mk @@ -118,6 +118,25 @@ define fixup-python-files endef endif +# Functions to detect overwritten files + +ifeq ($(BR2_PER_PACKAGE_DIRECTORIES),y) +# $(1): base directory to search in +# $(2): suffix of file (optional) +define pkg_detect_overwrite_before + find $(1) -type f -print0 | xargs -0 -r md5sum > $($(PKG)_DIR)/.files$(2).md5; +endef + +# $(1): base directory to search in +# $(2): suffix of file (optional) +define pkg_detect_overwrite_after + if test -s $($(PKG)_DIR)/.files$(2).md5 ; then \ + md5sum --quiet -c $($(PKG)_DIR)/.files$(2).md5 || \ + { echo "ERROR: package $($(PKG)_NAME) has overwritten files installed by a previous package, aborting."; exit 1; } ; \ + fi +endef +endif + # Functions to collect statistics about installed files # $(1): base directory to search in @@ -272,6 +291,8 @@ $(BUILD_DIR)/%/.stamp_configured: $(call fixup-python-files,$(NAME),$(HOST_DIR)) $(call fixup-python-files,$(NAME),$(STAGING_DIR)) $(foreach hook,$($(PKG)_POST_PREPARE_HOOKS),$(call $(hook))$(sep)) + @$(call pkg_detect_overwrite_before,$(TARGET_DIR)) + @$(call pkg_detect_overwrite_before,$(HOST_DIR),-host) $(foreach hook,$($(PKG)_PRE_CONFIGURE_HOOKS),$(call $(hook))$(sep)) $($(PKG)_CONFIGURE_CMDS) $(foreach hook,$($(PKG)_POST_CONFIGURE_HOOKS),$(call $(hook))$(sep)) @@ -396,6 +417,8 @@ $(BUILD_DIR)/%/.stamp_installed: @$(call pkg_size_after,$(STAGING_DIR),-staging) @$(call pkg_size_after,$(HOST_DIR),-host) @$(call check_bin_arch) + @$(call pkg_detect_overwrite_after,$(TARGET_DIR)) + @$(call pkg_detect_overwrite_after,$(HOST_DIR),-host) $(Q)touch $@ # Remove package sources -- 2.31.1